问题描述

我在使用docker-compose创建mysql的时候,遇到初始化创建数据库失败。问题记录如下:

docker-compose.yaml中mysql的部分如下:

  mysql:
    image: mysql:5.6
    ports:
      - "3306:3306"
    volumes:
      - ./cfg/mysql.conf:/etc/mysql/conf.d/mysql.cnf:ro
      - ./db/mysql/data:/var/lib/mysql/:rw
    restart: always
    networks:
      - default
    environment:
      TZ: "Asia/Shanghai"
      MYSQL_ROOT_PASSWORD: "123456"
      MYSQL_DATABASE: "typecho"
      MYSQL_USER: "typecho"
      MYSQL_PASSWORD: "123456"

操作过程

在第一次操作的时候,并没有加上MYSQL_DATABASE MYSQL_USERMYSQL_PASSWORD这三个字段,此时初始化mysql是成功的。此后,我修改了上面的yaml文件,加入了前面三个参数,重新build后发现定义的typecho库并没有被创建。

分析过程

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docker创建mysql容器本身其实是一个空数据库实例,然后在容器首次启动时执行了一个数据初始脚本:docker-entrypoint.sh。这个脚本读取定义的参数完成了数据库实例的初始化。根本脚本中的判断,当数据库的数据目录非空时,不会执行初始化操作,所以便找到了解决办法。

解决过程

  • 1、停止docker-compose
docker-compose stop
  • 2、清除宿主机数据目录
cd ./db/mysql/data
rm -fr ./*
  • 3、启动docker-compose
docker-compose up -d

至此,数据库初始化的问题就解决了。

这里贴一个完整的mysql5.6官方镜像中的docker-entrypoint.sh

#!/bin/bash
set -eo pipefail
shopt -s nullglob

# if command starts with an option, prepend mysqld
if [ "${1:0:1}" = '-' ]; then
    set -- mysqld "$@"
fi

# skip setup if they want an option that stops mysqld
wantHelp=
for arg; do
    case "$arg" in
        -'?'|--help|--print-defaults|-V|--version)
            wantHelp=1
            break
            ;;
    esac
done

# usage: file_env VAR [DEFAULT]
#    ie: file_env 'XYZ_DB_PASSWORD' 'example'
# (will allow for "$XYZ_DB_PASSWORD_FILE" to fill in the value of
#  "$XYZ_DB_PASSWORD" from a file, especially for Docker's secrets feature)
file_env() {
    local var="$1"
    local fileVar="${var}_FILE"
    local def="${2:-}"
    if [ "${!var:-}" ] && [ "${!fileVar:-}" ]; then
        echo >&2 "error: both $var and $fileVar are set (but are exclusive)"
        exit 1
    fi
    local val="$def"
    if [ "${!var:-}" ]; then
        val="${!var}"
    elif [ "${!fileVar:-}" ]; then
        val="$(< "${!fileVar}")"
    fi
    export "$var"="$val"
    unset "$fileVar"
}

# usage: process_init_file FILENAME MYSQLCOMMAND...
#    ie: process_init_file foo.sh mysql -uroot
# (process a single initializer file, based on its extension. we define this
# function here, so that initializer scripts (*.sh) can use the same logic,
# potentially recursively, or override the logic used in subsequent calls)
process_init_file() {
    local f="$1"; shift
    local mysql=( "$@" )

    case "$f" in
        *.sh)     echo "$0: running $f"; . "$f" ;;
        *.sql)    echo "$0: running $f"; "${mysql[@]}" < "$f"; echo ;;
        *.sql.gz) echo "$0: running $f"; gunzip -c "$f" | "${mysql[@]}"; echo ;;
        *)        echo "$0: ignoring $f" ;;
    esac
    echo
}

_check_config() {
    toRun=( "$@" --verbose --help --log-bin-index="$(mktemp -u)" )
    if ! errors="$("${toRun[@]}" 2>&1 >/dev/null)"; then
        cat >&2 <<-EOM

            ERROR: mysqld failed while attempting to check config
            command was: "${toRun[*]}"

            $errors
        EOM
        exit 1
    fi
}

# Fetch value from server config
# We use mysqld --verbose --help instead of my_print_defaults because the
# latter only show values present in config files, and not server defaults
_get_config() {
    local conf="$1"; shift
    "$@" --verbose --help --log-bin-index="$(mktemp -u)" 2>/dev/null | awk '$1 == "'"$conf"'" { print $2; exit }'
}

# allow the container to be started with `--user`
if [ "$1" = 'mysqld' -a -z "$wantHelp" -a "$(id -u)" = '0' ]; then
    _check_config "$@"
    DATADIR="$(_get_config 'datadir' "$@")"
    mkdir -p "$DATADIR"
    chown -R mysql:mysql "$DATADIR"
    exec gosu mysql "$BASH_SOURCE" "$@"
fi

if [ "$1" = 'mysqld' -a -z "$wantHelp" ]; then
    # still need to check config, container may have started with --user
    _check_config "$@"
    # Get config
    DATADIR="$(_get_config 'datadir' "$@")"

    if [ ! -d "$DATADIR/mysql" ]; then
        file_env 'MYSQL_ROOT_PASSWORD'
        if [ -z "$MYSQL_ROOT_PASSWORD" -a -z "$MYSQL_ALLOW_EMPTY_PASSWORD" -a -z "$MYSQL_RANDOM_ROOT_PASSWORD" ]; then
            echo >&2 'error: database is uninitialized and password option is not specified '
            echo >&2 '  You need to specify one of MYSQL_ROOT_PASSWORD, MYSQL_ALLOW_EMPTY_PASSWORD and MYSQL_RANDOM_ROOT_PASSWORD'
            exit 1
        fi

        mkdir -p "$DATADIR"

        echo 'Initializing database'
        # "Other options are passed to mysqld." (so we pass all "mysqld" arguments directly here)
        mysql_install_db --datadir="$DATADIR" --rpm --keep-my-cnf "${@:2}"
        echo 'Database initialized'

        SOCKET="$(_get_config 'socket' "$@")"
        "$@" --skip-networking --socket="${SOCKET}" &
        pid="$!"

        mysql=( mysql --protocol=socket -uroot -hlocalhost --socket="${SOCKET}" )

        for i in {30..0}; do
            if echo 'SELECT 1' | "${mysql[@]}" &> /dev/null; then
                break
            fi
            echo 'MySQL init process in progress...'
            sleep 1
        done
        if [ "$i" = 0 ]; then
            echo >&2 'MySQL init process failed.'
            exit 1
        fi

        if [ -z "$MYSQL_INITDB_SKIP_TZINFO" ]; then
            # sed is for https://bugs.mysql.com/bug.php?id=20545
            mysql_tzinfo_to_sql /usr/share/zoneinfo | sed 's/Local time zone must be set--see zic manual page/FCTY/' | "${mysql[@]}" mysql
        fi

        if [ ! -z "$MYSQL_RANDOM_ROOT_PASSWORD" ]; then
            export MYSQL_ROOT_PASSWORD="$(pwgen -1 32)"
            echo "GENERATED ROOT PASSWORD: $MYSQL_ROOT_PASSWORD"
        fi

        rootCreate=
        # default root to listen for connections from anywhere
        file_env 'MYSQL_ROOT_HOST' '%'
        if [ ! -z "$MYSQL_ROOT_HOST" -a "$MYSQL_ROOT_HOST" != 'localhost' ]; then
            # no, we don't care if read finds a terminating character in this heredoc
            # https://unix.stackexchange.com/questions/265149/why-is-set-o-errexit-breaking-this-read-heredoc-expression/265151#265151
            read -r -d '' rootCreate <<-EOSQL || true
                CREATE USER 'root'@'${MYSQL_ROOT_HOST}' IDENTIFIED BY '${MYSQL_ROOT_PASSWORD}' ;
                GRANT ALL ON *.* TO 'root'@'${MYSQL_ROOT_HOST}' WITH GRANT OPTION ;
            EOSQL
        fi

        "${mysql[@]}" <<-EOSQL
            -- What's done in this file shouldn't be replicated
            --  or products like mysql-fabric won't work
            SET @@SESSION.SQL_LOG_BIN=0;

            DELETE FROM mysql.user WHERE user NOT IN ('mysql.sys', 'mysqlxsys', 'root') OR host NOT IN ('localhost') ;
            SET PASSWORD FOR 'root'@'localhost'=PASSWORD('${MYSQL_ROOT_PASSWORD}') ;
            GRANT ALL ON *.* TO 'root'@'localhost' WITH GRANT OPTION ;
            ${rootCreate}
            DROP DATABASE IF EXISTS test ;
            FLUSH PRIVILEGES ;
        EOSQL

        if [ ! -z "$MYSQL_ROOT_PASSWORD" ]; then
            mysql+=( -p"${MYSQL_ROOT_PASSWORD}" )
        fi

        file_env 'MYSQL_DATABASE'
        if [ "$MYSQL_DATABASE" ]; then
            echo "CREATE DATABASE IF NOT EXISTS \`$MYSQL_DATABASE\` ;" | "${mysql[@]}"
            mysql+=( "$MYSQL_DATABASE" )
        fi

        file_env 'MYSQL_USER'
        file_env 'MYSQL_PASSWORD'
        if [ "$MYSQL_USER" -a "$MYSQL_PASSWORD" ]; then
            echo "CREATE USER '$MYSQL_USER'@'%' IDENTIFIED BY '$MYSQL_PASSWORD' ;" | "${mysql[@]}"

            if [ "$MYSQL_DATABASE" ]; then
                echo "GRANT ALL ON \`$MYSQL_DATABASE\`.* TO '$MYSQL_USER'@'%' ;" | "${mysql[@]}"
            fi

            echo 'FLUSH PRIVILEGES ;' | "${mysql[@]}"
        fi

        echo
        ls /docker-entrypoint-initdb.d/ > /dev/null
        for f in /docker-entrypoint-initdb.d/*; do
            process_init_file "$f" "${mysql[@]}"
        done

        if [ ! -z "$MYSQL_ONETIME_PASSWORD" ]; then
            "${mysql[@]}" <<-EOSQL
                ALTER USER 'root'@'%' PASSWORD EXPIRE;
            EOSQL
        fi
        if ! kill -s TERM "$pid" || ! wait "$pid"; then
            echo >&2 'MySQL init process failed.'
            exit 1
        fi

        echo
        echo 'MySQL init process done. Ready for start up.'
        echo
    fi
fi

exec "$@"